Tokyo, Japan (CNN) -- Social network Web sites have changed the way we communicate and ingest media. Now Japan's policymakers are feeling the force of social networking on the country's consumer prices.

Seventy thousand penny pinching housewives are members of Mainichi Tokubai, a user-driven site that delivers Tokyo's best grocery store prices to your fingertips.

No more flipping through hundreds of regional ads for the sales -- that's "so last year," says Satomi Sato. Every morning, she wakes up at the crack of dawn and scours just a couple of supermarket flyers in her paper.

On the morning we joined her, pork and scallions were the best deals she could find.

"There's so much information we can't get without the Internet," Sato said. "I can't get the information on flyers that aren't distributed to my neighborhood."

But the Web site has changed all that. She inputs the deals from her neighborhood into the Mainichi Tokubai site, just one of 25,000 other moms dubbed "regional correspondents."

On the other end, logging into the site from her mobile phone, is Hiroe Ishimoto. The Web site declares that Belc grocery store is having a huge deal on eggs today: only about $1 for a dozen.

Clicking through the site, Ishimoto buys sprouts, tomatoes and eggs but passes on the squash and broccoli -- that she can get cheaper at another supermarket, says the Web site.

"I always buy cheap stuff," says Ishimoto, gripping her mobile phone, as she pushes her shopping cart. "I live with the comfort of knowing that I never get a bad deal."

The Mainichi Tokubai site is social media at its best, says creator Yasuyo Fukui. She considers it "by the housewives, for the housewives," a user-generated site that benefits everyone who logs in.

"The charm of this site is that it's not just about looking for cheap food," said

Fukui, who says the site puts buying power into the hands of the users.

"The housewives check information like where the product comes from. They're everyday shoppers and provide a different perspective from the retailers."

Fukui says subscribers to the Web site jumped 20 percent when Japan's economy slipped into recession.

"Husbands' salaries either stayed the same or dropped. Housewives still have to buy food for the family, and our site helps."

But retailers and policymakers, grappling with falling consumer prices and sentiment, call these sites problematic.

"We understand consumers want the best deals," said Shoichi Ogasawara, from the Japan Chain Stores Association, calling the social network site a natural extension of consumer behavior in our information age. But he says supermarket prices have fallen for 13 years in a row in Japan, and the sites are making it difficult to turn around the trend.

"We can't do anything about these networking sites, except to try and make our products more attractive for the price."

Japan's government reports core consumer prices fell 1.2 percent in March from a year before, the thirteenth straight month of decline.

So far, the Bank of Japan and the national government haven't been able to turn around the deflationary trend, which has been a major drag on the country's recovery.

When asked if Hiroe Ishimoto is contributing to the deflationary mood in Japan with her devotion to the Web site, she said tersely, "I have a limited daily budget for my family. Sorry, but I can't worry about it at all."

She's shaved several dollars off her grocery bill today and that's what matters to her, she says.

As far as the policymakers are concerned, they're the ones who are going to have to catch up with today's consumer, she said, not the other way around.